Balloon Catheter

ABSTRACT

A balloon catheter includes a balloon/shaft assembly and a linear member. The balloon/shaft assembly includes a catheter shaft extending from a proximal end to a distal end and a balloon connected to the catheter shaft. The linear member straddles an inflatable region of the balloon and is mounted on the balloon/shaft assembly. The linear member includes a hard portion and a flexible portion. The hard portion includes at least an outer portion disposed on an opposite side to an inner portion facing the inflatable region, of a portion disposed along an outer peripheral surface of the inflatable region in an inflated state. The flexible portion is a portion other than the hard portion. The flexible portion is extendable and has a lower hardness than the hard portion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of prior application Ser. No.15/727,665, filed Oct. 9, 2017, which is a continuation-in-part ofInternational Application No. PCT/JP2016/061484, filed Apr. 8, 2016,which claims priority from Japanese Patent Applications No. 2015-080627,filed on Apr. 10, 2015 and No. 2015-248540, filed on Dec. 21, 2015. Thedisclosure of the foregoing applications is hereby incorporated byreference in its entirety.

BACKGROUND

The present disclosure relates to a balloon catheter.

A balloon catheter is known that is used in treatments that dilate aconstricted location of a blood vessel. For example, the known ballooncatheter is provided with a catheter tube, a balloon, three linearmembers, and a fixed cone-shaped portion. The catheter tube (sometimesalso referred to as a “catheter shaft”) has an inner tube and an outertube. The balloon is joined to the outer tube and the inner tube. Theballoon inflates when a compressed fluid is supplied. The three linearmembers are disposed on the outer peripheral side of the balloon. Adistal end side of the fixed cone-shaped portion is joined to a distalend of the inner tube. A proximal end side of the fixed cone-shapedportion is joined to the three linear members. The fixed cone-shapedportion is elastically deformable. The three linear members move in adirection away from the inner tube in accordance with the inflation ofthe balloon. The fixed cone-shaped portion extends in response to themovement of the three linear members in the direction away from theinner tube. The fixed cone-shaped portion contracts in accordance withthe deflation of the balloon, and the three linear members move in adirection approaching the inner tube.

SUMMARY

In the case of the known balloon catheter, the fixed cone-shaped portionjoined to the distal end of the inner tube has an outer diameter that issufficiently larger than the inner tube even in a deflated state. Thus,from the point of view of crossability, there is room for improvement.

Various embodiments of the broad principles derived herein provide aballoon catheter having superior crossability.

Embodiments provide a balloon catheter that includes a balloon/shaftassembly and a linear member. The balloon/shaft assembly includes acatheter shaft extending from a proximal end to a distal end and aballoon connected to the catheter shaft. The balloon has an inflatableregion configured to inflate outward in a radial direction around thecatheter shaft. The linear member straddles the inflatable region of theballoon and is mounted on the balloon/shaft assembly at a distal endposition located further toward the distal end side than the inflatableregion and at a proximal end position located further toward theproximal end side than the inflatable region. The linear member includesa hard portion and a flexible portion. The hard portion includes atleast an outer portion disposed on an opposite side to an inner portionfacing the inflatable region, of a portion disposed along an outerperipheral surface of the inflatable region in an inflated state. Theflexible portion is a portion other than the hard portion. The flexibleportion is extendable and has a lower hardness than the hard portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be described below in detail with reference to theaccompanying drawings in which:

FIG. 1 is a side view of a balloon catheter according to a firstembodiment;

FIG. 2 is a side view of a balloon and a linear member in a deflatedstate;

FIG. 3 is a cross-sectional view in the direction of arrows along a lineI-I shown in FIG. 2;

FIG. 4 is a cross-sectional view of the balloon and the linear member inthe deflated state;

FIG. 5 is a side view of the balloon and the linear member in aninflated state;

FIG. 6 is a cross-sectional view in the direction of arrows along a lineII-II shown in FIG. 5;

FIG. 7 is a cross-sectional view of the balloon and the linear member inthe inflated state;

FIG. 8 shows a side view and cross-sectional views of the linear member4;

FIG. 9 is a cross-sectional view of the balloon and the linear memberaccording to a second embodiment;

FIG. 10 is a cross-sectional view of the balloon and a linear memberaccording to a third embodiment;

FIG. 11 shows a side view and cross-sectional views of the linearmember;

FIG. 12 is a cross-sectional view of the balloon and a linear memberaccording to a fourth embodiment;

FIG. 13 shows a side view and cross-sectional views of the linearmember;

FIG. 14 is a cross-sectional view of the balloon and a linear memberaccording to a fifth embodiment;

FIG. 15 shows a side view and cross-sectional views of the linearmember;

FIG. 16 is a side view of the balloon and a linear member according to asixth embodiment;

FIG. 17 is a cross-sectional view in the direction of arrows along aline III-III shown in FIG. 16;

FIG. 18 is a cross-sectional view of the balloon and the linear memberin the inflated state;

FIG. 19 shows a side view and cross-sectional views of the linearmember;

FIG. 20 is a cross-sectional view of an expanded part of the linearmember according to a seventh embodiment;

FIG. 21 is a cross-sectional view of an expanded part of the linearmember according to an eighth embodiment; and

FIG. 22 is a cross-sectional view of an expanded part of the linearmember according to a ninth embodiment.

DETAILED DESCRIPTION First Embodiment

Hereinafter, a balloon catheter 10 according to a first embodiment ofthe present disclosure will be explained with reference to FIG. 1 toFIG. 8. As shown in FIG. 1, the balloon catheter 10 has a catheter shaft2, a balloon 3, and linear members 4A, 4B, and 4C (refer to FIG. 3,hereinafter collectively referred to as “linear members 4”).Hereinafter, the catheter shaft 2 and the balloon 3 are collectivelyreferred to as a “balloon/shaft assembly 25.” The balloon 3 is connectedto an end portion on one side of the catheter shaft 2. The linearmembers 4 are disposed on the outside of the balloon 3 in an inflatedstate. The balloon catheter 10 is used in a state in which a hub 5 isconnected to an end portion on the other side of the catheter shaft 2.The hub 5 can supply compressed fluid to the balloon 3 via the cathetershaft 2. Hereinafter, the one end (of both ends) of the catheter shaft 2on the one side is referred to as a “distal end.” The other end (of bothends) of the catheter shaft 2 is referred to as a “proximal end.” Adirection extending along the catheter shaft 2 is referred to as an“extending direction.” In a plane orthogonal to the extending direction,of a radial direction taking a center of a cross section of the cathetershaft 2 as a reference, a side closer to the center of the cross sectionof the catheter shaft 2 is referred to as an “inner side” and a sidefurther away from the center of the cross section of the catheter shaft2 is referred to as an “outer side.”

Catheter Shaft 2

As shown in FIG. 4 and FIG. 7, the catheter shaft 2 has an outer tube 21and an inner tube 22. The outer tube 21 and the inner tube 22 are bothflexible tubular members. The outer tube 21 has a lumen 213, which is aspace surrounded by an inner surface 212, which is a surface on theinner side of the outer tube 21. The inner tube 22 has a lumen 223,which is a space surrounded by an inner surface 222, which is a surfaceon the inner side of the inner tube 22. The outer tube 21 and the innertube 22 are formed of a polyamide resin. The inner diameter of the outertube 21 is larger than the outer diameter of the inner tube 22.

Apart from a predetermined portion on the distal end side, the innertube 22 is disposed inside the lumen 213 of the outer tube 21. Thepredetermined portion on the distal end side of the inner tube 22protrudes toward the distal end side from an end (hereinafter referredto as a “distal end 211”) on the distal end side of the outer tube 21.The end (hereinafter referred to as a “distal end 221”) on the distalend side of the inner tube 22 is disposed further toward the distal endside than the distal end 211 of the outer tube 21. Hereinafter, thepredetermined portion on the distal end side of the inner tube 22 isreferred to as a “protruding portion 225.” Radiopaque markers(hereinafter simply referred to as “markers”) 22A and 22B are fitted tothe protruding portion 225 of the inner tube 22. Resin into which aradiopaque material is mixed is used as the material of the markers 22Aand 22B. The markers 22A and 22B are fixed to an outer surface 224,which is an outer peripheral surface of the inner tube 22, as a resultof cylindrical members formed of the above-described material beingcrimped onto the protruding portion 225 of the inner tube 22. Themarkers 22A and 22B have a predetermined length in the extendingdirection. The markers 22A and 22B do not allow the passage ofradiation. The marker 22A is disposed further toward the distal end sidethan the marker 22B. The markers 22A and 22B are separated from eachother in the extending direction.

As shown in FIG. 2, FIG. 4, FIG. 5, and FIG. 7, of an outer surface 214,which is the outer peripheral surface of the outer tube 21, a mountingmember 21A is mounted on a portion further toward the proximal end sidethan the distal end 211. The mounting member 21A is a cylindrical memberthat can move along the extending direction. The inner diameter of themounting member 21A is larger than the outer diameter of the outer tube21. A thermoplastic resin, such as a polyamide resin or the like, isused as the material of the mounting member 21A.

As shown in FIG. 4 and FIG. 7, the compressed fluid supplied from thehub 5 (refer to FIG. 1) flows through a space of the lumen 213 of theouter tube 21 other than the lumen 223 of the inner tube 22. The balloon3 inflates (refer to FIG. 5 to FIG. 7) in accordance with the supply ofthe compressed fluid. A guide wire that is not shown in the drawings isinserted through the lumen 223 of the inner tube 22

The material of the outer tube 21 and the inner tube 22 is not limitedto the polyamide resin, and can be changed to another flexible material.For example, a synthetic resin material, such as a polyethylene resin, apolypropylene resin, a polyurethane resin, a polyimide resin and thelike, may be used as the material of the outer tube 21 and the innertube 22. Additives may be mixed with the synthetic resin material.Different synthetic resin materials may be used as the materials of theouter tube 21 and the inner tube 22, respectively. The material of themarkers 22A and 22B is not limited to the resin into which theradiopaque material is mixed, and can be changed to another materialthat does not allow the passage of radiation. For example, a resin onwhich a radiopaque material is deposited, or a material such as metal orthe like that does not allow the passage of radiation may be used as thematerial of the markers 22A and 22B.

Balloon 3

As shown in FIG. 2 to FIG. 4, the balloon 3 deflates to the inner sidewhen the compressed fluid is not supplied. As shown in FIG. 5 to FIG. 7,the balloon 3 inflates to the outer side when the compressed fluid issupplied. The balloon 3 is formed of a polyamide resin. As shown in FIG.2, FIG. 4, FIG. 5, and FIG. 7, the balloon 3 includes a proximal endside leg portion 31, a proximal end side cone region 32, an inflatableregion 33, a distal end side cone region 34, and a distal end side legportion 35. The proximal end side leg portion 31, the proximal end sidecone region 32, the inflatable region 33, the distal end side coneregion 34, and the distal end side leg portion 35 respectivelycorrespond to portions of the balloon 3 divided into five in theextending direction. The length of the inflatable region 33 in theextending direction is longer than the respective lengths in theextending direction of the proximal end side leg portion 31, theproximal end side cone region 32, the distal end side cone region 34,and the distal end side leg portion 35.

As shown in FIG. 4 and FIG. 7, the proximal end side leg portion 31 isconnected, by thermal welding, to the outer surface 214 that is theouter peripheral surface of the outer tube 21, at a portion locatedfurther toward the proximal end side than the distal end 211 and furthertoward the distal end side than the portion on which the mounting member21A is mounted. The proximal end side cone region 32 is adjacent to thedistal end side of the proximal end side leg portion 31. The inflatableregion 33 is adjacent to the distal end side of the proximal end sidecone region 32. The distal end side cone region 34 is adjacent to thedistal end side of the inflatable region 33. The distal end side legportion 35 is adjacent to the distal end side of the distal end sidecone region 34. The distal end side leg portion 35 is connected, bythermal welding, to the outer surface 224 of the protruding portion 225of the inner tube 22, at a portion located further toward the proximalend side than the distal end 221. The proximal end side leg portion 31,the proximal end side cone region 32, the inflatable region 33, thedistal end side cone region 34, and the distal end side leg portion 35are disposed side by side in that order from the proximal end sidetoward the distal end side. The proximal end side cone region 32, theinflatable region 33, the distal end side cone region 34, and the distalend side leg portion 35 cover the protruding portion 225 of the innertube 22 from outside.

As shown in FIG. 2 to FIG. 4, three pleats are formed by the balloon 3in the deflated state. The balloon 3 is a three pleat type balloon. Asshown in FIG. 3, in the deflated state, the balloon 3 is folded over soas to form three pleats 3A, 3B, and 3C. Each of the pleats 3A, 3B, and3C is wrapped around the protruding portion 225 of the inner tube 22. Inthis state, the pleat 3A covers the linear member 4A, which will bedescribed later, from outside. The pleat 3B covers the linear member 4B,which will be described later, from outside. The pleat 3C covers thelinear member 4C, which will be described later, from outside. Thepleats 3A, 3B, and 3C are also called “flaps” and “wings.”

The inflated state of the balloon 3 will be explained with reference toFIG. 5 to FIG. 7. As shown in FIG. 6, the cross-sectional shape of theballoon 3 is circular. As shown in FIG. 5 and FIG. 7, the proximal endside cone region 32 has a tapered shape. The diameter of the proximalend side cone region 32 increases continuously and linearly from theproximal end side toward the distal end side. The diameter of theinflatable region 33 is the same across the whole length in theextending direction. The distal end side cone region 34 has a taperedshape. The diameter of the distal end side cone region 34 decreasescontinuously and linearly from the proximal end side toward the distalend side. The diameter of the cross section of the balloon 3 changes ina stepped manner between the proximal end side cone region 32, theinflatable region 33, and the distal end side cone region 34. Theinflatable region 33 is a portion of the balloon 3 having the maximumdiameter.

As shown in FIG. 7, a boundary of the inflatable region 33 on the distalend side is aligned, in the extending direction, with a position P11 ofan end portion on the distal end side of the marker 22A. In other words,the boundary of the inflatable region 33 on the distal end side is aposition of a boundary between the inflatable region 33 and the distalend side cone region 34. A boundary of the inflatable region 33 on theproximal end side is aligned, in the extending direction, with aposition P21 of an end portion on the proximal end side of the marker22B. In other words, the boundary of the inflatable region 33 on theproximal end side is a position of a boundary between the inflatableregion 33 and the proximal end side cone region 32.

The material of the balloon 3 is not limited to the polyamide resin, andcan be changed to another flexible material. For example, a polyethyleneresin, a polypropylene resin, a polyurethane resin, a polyimide resin,silicone rubber, natural rubber, and the like may be used as thematerial of the balloon 3. In the above description, the method ofconnecting the outer tube 21 and the inner tube 22 to the balloon 3 isnot limited to the thermal welding. For example, each of the outer tube21 and the inner tube 22 may be connected using an adhesive.

Linear Member 4

The linear member 4 will be explained with reference to FIG. 4 to FIG.8. The linear member 4 has a restoring force with respect to bendingdeformation. The linear member 4 is a monofilament-shaped elastic body.The linear members 4A, 4B, and 4C have the same shape. The linear member4 extends along the extending direction.

As shown in FIG. 4, FIG. 5, and FIG. 7, an end portion on the distal endside of the linear member 4 is connected, by thermal welding, to aportion of the outer peripheral surface of the distal end side legportion 35 of the balloon 3 that is further to the distal end side thanthe center in the extending direction. Hereinafter, a position at whichthe end portion on the distal end side of the linear member 4 isconnected, in the extending direction of the balloon catheter 10, isreferred to as a “distal end position M1.” In the extending direction,the distal end position M1 is disposed further toward the distal endside than the inflatable region 33 of the balloon 3 in the inflatedstate. The distal end position M1 corresponds to a position furthertoward the distal end side than the center, in the extending direction,of the distal end side leg portion 35 of the balloon 3. The end portionson the distal end side of each of the linear members 4A, 4B, and 4C areconnected, respectively, to positions that divide the outer peripheralsurface of the distal end side leg portion 35 of the balloon 3 intothree equal parts in the circumferential direction.

An end portion on the proximal end side of the linear member 4 isconnected, by thermal welding, to a portion of the outer peripheralsurface of the mounting member 21A located further toward the proximalend side than the center in the extending direction. Hereinafter, aposition at which the end portion on the proximal end side of the linearmember 4 is connected, in the extending direction of the ballooncatheter 10, is referred to as a “proximal end position M2.” In theextending direction, the proximal end position M2 is disposed furthertoward the proximal end side than the inflatable region 33 of theballoon 3 in the inflated state. The end portions on the proximal endside of each of the linear members 4A, 4B, and 4C are connected,respectively, to positions that divide the outer peripheral surface ofthe mounting member 21A into three equal parts in the circumferentialdirection. The linear member 4 is connected at the distal end positionM1 and the proximal end position M2, and is not connected to the balloon3 at other portions thereof.

The linear member 4 is disposed between the distal end position M1 andthe proximal end position M2 so as to straddle the inflatable region 33of the balloon 3. As shown in FIG. 6, when the balloon 3 is in theinflated state, the linear members 4A, 4B, and 4C extend in straightlines in the extending direction, respectively, at positions that dividethe outer peripheral surface of the inflatable region 33 of the balloon3 into three approximately equal parts in the circumferential direction.

As shown in FIG. 4, FIG. 5, and FIG. 7, the linear member 4 has aflexible portion 41, and a hard portion 42. The flexible portion 41extends between the proximal end position M2 and the distal end positionM1. The flexible portion 41 includes a first portion 411, a secondportion 412, and a third portion 413. The first portion 411, the secondportion 412, and the third portion 413 respectively correspond toportions of the flexible portion 41 that is divided into three in theextending direction. An end portion on the proximal end side of thefirst portion 411 is connected to the outer peripheral surface of themounting member 21A, at the proximal end position M2. The second portion412 is adjacent to the distal end side of the first portion 411. Thethird portion 413 is adjacent to the distal end side of the secondportion 412. An end portion on the distal end side of the third portion413 is connected to the outer peripheral surface of the distal end sideleg portion 35 of the balloon 3, at the distal end position M1. The hardportion 42 is laminated on the second portion 412 of the flexibleportion 41, at a portion on the opposite side to a portion facing theballoon 3.

FIG. 8 shows cross sections of the linear member 4 at each of a lineA1-A1, a line B1-B1, and a line C1-C1. The cross-sectional shape of thelinear member 4 is a trapezoid shape or a triangular shape. This isexplained more specifically below.

The cross-sectional shape of the flexible portion 41 (the first portion411 to the third portion 413) is a trapezoid shape. Hereinafter, of thefirst portion 411 of the flexible portion 41, a portion facing theballoon 3 in the inflated state (refer to FIG. 6) is referred to as an“inner portion 411A.” Of the first portion 411, a portion on theopposite side to the inner portion 411A is referred to as an “outerportion 411B.” Of the second portion 412 of the flexible portion 41, aportion facing the balloon 3 in the inflated state is referred to as an“inner portion 412A.” Of the first portion 412, a portion on theopposite side to the inner portion 412A is referred to as an “outerportion 412B.” Of the third portion 413 of the flexible portion 41, aportion facing the balloon 3 is referred to as an “inner portion 413A.”Of the third portion 413, a portion on the opposite side to the innerportion 413A is referred to as an “outer portion 413B.” The innerportions 411A, 412A, and 413A and the outer portions 411B, 412B, and413B respectively correspond to a lower base and an upper base of thetrapezoid that is the cross-sectional shape.

A length between the inner portion 413A and the outer portion 413B ofthe third portion 413, namely, a thickness R13 of a portion of theflexible portion 41 located further toward the distal end side than thehard portion 42, is 0.15 mm. A length between the inner portion 411A andthe outer portion 411B of the first portion 411, namely, a thickness R11of a portion of the flexible portion 41 located further toward theproximal end side than the hard portion 42, is 0.23 mm. The thicknessR13 is narrower than the thickness R11.

The shape of the cross section of the hard portion 42 is an equilateraltriangle shape having the outer portion 412B of the second portion 412as one side. The hard portion 42 protrudes to the outside from the outerportion 412B of the second portion 412 of the flexible portion 41.Hereinafter, an end portion on the outside of the hard portion 42 isreferred to as an “outer portion 42B.” The outer portion 42B correspondsto an apex of the equilateral triangle shape. The outer portion 42B ispeaked. A length between the inner portion 412A and the outer portion42B, namely a thickness R12 of the portion at which the second portion412 of the flexible portion 41 and the hard portion 42 are laminated, is0.4 mm.

An end surface on the distal end side of the hard portion 42 is referredto as a “distal end surface 42S.” A virtual first direction D11 isdefined that extends toward the outside along the distal end surface 42Sof the hard portion 42. The first direction D11 is inclined toward theproximal end side with respect to a direction orthogonal to theextending direction. An end surface on the proximal end side of the hardportion 42 is referred to as a “proximal end surface 42K.” A virtualsecond direction D12 is defined that extends toward the outside alongthe proximal end surface 42K of the hard portion 42. The seconddirection D12 is inclined toward the distal end side with respect to thedirection orthogonal to the extending direction. An acute angle, ofangles formed between the first direction D11 and the extendingdirection, is defined as a first angle θ11. The first angle θ11 is anangle between 4 to 13 degrees, for example. The first angle θ11 ispreferably 5 degrees. An acute angle, of angles formed between thesecond direction D12 and the extending direction, is defined as a secondangle θ12. The second angle θ12 is an angle between 5 to 16 degrees, forexample. The second angle θ12 is preferably 16 degrees. The preferablefive degrees of the first angle θ11 is smaller than the preferablesixteen degrees of the second angle θ12.

As shown in FIG. 7, when the balloon 3 is in the inflated state, aposition of a boundary on the distal end side of the second portion 412of the flexible portion 41, namely, a position of a boundary between thesecond portion 412 and the third portion 413, is aligned, in theextending direction, with the position P11 of the end portion on thedistal end side of the marker 22A. A position of a boundary on theproximal end side of the second portion 412 of the flexible portion 41,namely, a position of a boundary between the first portion 411 and thesecond portion 412, is aligned, in the extending direction, with theposition P21 of the end portion on the proximal end side of the marker22B.

As described above, the boundary on the distal end side of theinflatable region 33 is aligned, in the extending direction, with theposition P11 of the end portion on the distal end side of the marker22A. The boundary on the proximal end side of the inflatable region 33is aligned, in the extending direction, with the position P21 of the endportion on the proximal end side of the marker 22B. Thus, when theballoon 3 is in the inflated state, the inflatable region 33 of theballoon 3, the second portion 412 of the flexible portion 41, and thehard portion 42 are all disposed in the same position in the extendingdirection. The second portion 412 of the flexible portion 41 is disposedalong the outer peripheral surface of the inflatable region 33 of theballoon 3. The inner portion 412A of the second portion 412 of theflexible portion 41 faces the inflatable region 33 of the balloon 3. Thehard portion 42 is disposed on the opposite side to the portion facingthe inflatable region 33 of the balloon 3, namely, on the opposite sideto the inner portion 412A of the second portion 412 of the flexibleportion 41.

The linear member 4 is formed of a polyamide resin. More specifically,the flexible portion 41 is formed of a polyamide elastomer. The hardnessof the flexible portion 41 is a value within a range of D25 to D63 asprescribed in ISO 868. The hard portion 42 is formed of a polyamideresin. The hardness of the hard portion 42 is a value within a range ofD70 to D95 as prescribed in ISO 868.The flexible portion 41 is softerthan the hard portion 42. In comparison to the hard portion 42, theflexible portion 41 has excellent extendability.

A state of the linear member 4 when the balloon 3 inflates as a resultof the compressed fluid being supplied from the hub 5 will be explained.In accordance with the inflation of the balloon 3, the hard portion 42of the linear member 4 separates from the protruding portion 225 of theinner tube 22 (refer to FIG. 7). At that time, of the flexible portion41 of the linear member 4, the first portion 411 and the third portion413 elastically deform so as to extend along the extending direction,while the second portion 412 on which the hard portion 42 is laminateddoes not. As a result, the hard portion 42 easily separates from theprotruding portion 225 of the inner tube 22. The inner surface 412A ofthe second portion 412 of the flexible portion 41 is disposed along theouter peripheral surface of the inflatable region 33 of the balloon 3.The outer portion 42B (refer to FIG. 8) of the hard portion 42 protrudesto the outside from the outer portion 412B of the second portion 412 ofthe flexible portion 41 (refer to FIG. 6). As described above, incomparison to the flexible portion 41, the hard portion 42 does noteasily extend. Thus, even when the balloon 3 inflates, the secondportion 412 of the flexible portion 41 of the linear member 4 does notextend to the same extent as the first portion 411 and the third portion413 of the flexible portion 41.

A state of the linear member 4 when the balloon 3 deflates as a resultof the compressed fluid being discharged from the balloon 3 in theinflated state will be explained. When the balloon 3 is deflated, thefirst portion 411 and the third portion 413 of the flexible portion 41of the linear member 4 that have extended in the extending directioncontract due to the restoring force. The hard portion 42 of the linearmember 4 approaches the protruding portion 225 of the inner tube 22(refer to FIG. 4). Warping of the linear member 4 is suppressed by thecontraction of the first portion 411 and the third portion 413 of theflexible portion 41. The linear member 4A is covered from the outside bythe pleat 3A. The linear member 4B is covered from the outside by thepleat 3B. The linear member 4C is covered from the outside by the pleat3C (refer to FIG. 3).

As long as the flexible portion 41 and the hard portion 42 of the linearmember 4 have favorable hardness and extendability, the material thereofis not limited to the polyamide resin, and another synthetic resin canbe used. The material is not limited to the synthetic resin, andstainless steel, a Ni—Ti alloy, or carbon fiber may be used.

Main Operations and Effects of First Embodiment

In the balloon catheter 10 of the first embodiment, when the balloon 3inflates, since the inflatable region 33 moves to the outside, the hardportion 42 of the linear member 4 that is disposed along the outerperipheral surface of the inflatable region 33 also tries to move to theoutside. In response to this, of the flexible portion 41 of the linearmember 4, the first portion 411 and the third portion 413 on which thehard portion 42 is not laminated elastically deform so as to extendalong the extending direction. As a result, the hard portion 42 caneasily move to the outside. The outer portion 42B of the hard portion 42of the linear member 4 protrudes to the outside from the outer portion412B on the opposite side to the inner portion 412A that faces the outerperipheral surface of the balloon 3. The hard portion 42 has a higherhardness than the flexible portion 41. Thus, in a state in which theballoon 3 is disposed in a constricted portion of a blood vessel, whenthe balloon 3 is inflated, the hard portion 42 acts appropriately on theconstricted portion of the blood vessel. For example, the hard portion42 is peaked at the outer portion 42B, and thus the hard portion 42 caneasily bite into a lesioned part (not shown in the drawings) of theblood vessel. As a result, in a state in which the linear member 4causes the balloon 3 to be in a state of not easily slipping withrespect to the lesioned part of the blood vessel, the lesioned part canbe expanded from the inside by the inflation of the balloon 3.

In the balloon catheter 10, the first portion 411 and the third portion413 of the flexible portion 41 are caused to extend in accordance withthe inflation of the balloon 3, and the hard portion 42 is caused tomove to the outside. In this way, the balloon catheter 10 can cause thehard portion 42 to act on the constricted portion inside the bloodvessel. As a result, other than the linear members 4, the ballooncatheter 10 does not require a member that is necessary to be able tomove the hard portion 42 to the outside. Thus, when a user tries to movethe balloon 3 as far as the constricted portion of the blood vessel, theballoon catheter 10 can inhibit obstruction of the movement of theballoon 3 by the member other than the linear members 4. In this way,the balloon catheter 10 can cause the balloon 3 to appropriatelyapproach and be disposed at the constricted portion of the blood vessel.

The flexible portion 41 of the linear member 4 extends between thedistal end position M1 and the proximal end position M2. Of the flexibleportion 41, the hard portion 42 is laminated on the second portion 412that is disposed along the outer peripheral surface of the inflatableregion 33 in the inflated state. When the balloon 3 is in the inflatedstate, the hard portion 42 protrudes to the outside from the outerportion 412B of the second portion 412 of the flexible portion 41. Thus,the balloon catheter 10 can inhibit the hard portion 42 from obstructingthe extending of the first portion 411 and the third portion 413 of theflexible portion 41, on which the hard portion 42 is not laminated. Theflexible portion 41 extends appropriately at the first portion 411 andthe third portion 413. Thus, the balloon catheter 10 can easily move thehard portion 42 to the outside in accordance with the inflation of theballoon 3.

The first direction D11, which extends to the outside along the distalend surface 42S that is the end portion of the hard portion 42 on thedistal end side, is inclined toward the proximal end side. In this case,when the balloon catheter 10 moves inside the blood vessel in the courseof the user causing the balloon 3 to approach the constricted portion ofthe blood vessel, the linear member 4 can be inhibited from catching onthe inner wall of the blood vessel. Thus, the user can smoothly move theballoon 3 as far as the constricted portion of the blood vessel.Further, the second direction D12, which extends to the outside alongthe proximal end surface 42K that is the end portion of the hard portion42 on the proximal end side, is inclined toward the distal end side. Inthis case, when the balloon catheter 10 moves inside the blood vessel inthe course of the user pulling the balloon catheter 10 out from theblood vessel, the linear member 4 can be inhibited from catching on theinner wall of the blood vessel. Thus, the user can easily pull theballoon catheter 10 out from the blood vessel.

With respect to the flexible portion 41, the thickness R13 of the thirdportion 413 located further toward the distal end side than the hardportion 42 is narrower than the thickness R11 of the first portion 411located further toward the proximal end side than the hard portion 42.In this case, in comparison to a case in which the thickness R13 isthicker than the thickness R11, or a case in which the thicknesses R11and R13 are the same as each other, the balloon catheter 10 can make thediameter of the distal end portion smaller. Thus, the user can cause theballoon 3 of the balloon catheter 10 to move as far as the constrictedportion of the blood vessel using less force.

The first angle θ11, which is the acute angle of the angles formedbetween the extending direction and the first direction D11, is smallerthan the second angle θ12, which is the acute angle of the angles formedbetween the extending direction and the second direction D12. In thiscase, the balloon catheter 10 can use the portion of the distal endsurface 42S to reduce a rate of change of the hardness in the extendingdirection of the linear member 4. Further, since the first angle θ11 issmall, the balloon catheter 10 can inhibit the linear members 4 fromcatching on the inner wall of the blood vessel when the user moves theballoon catheter 10 as far as the constricted portion inside the bloodvessel. In this way, the user can easily move the balloon 3 as far asthe constricted portion of the blood vessel.

The protruding portion 225 of the inner tube 22 is provided with themarkers 22A and 22B in the positions separated from each other in theextending direction. The position P11 of the distal end side of thedistal end side marker 22A is aligned with the position of the boundaryof the distal end side of the inflatable region 33. The position P21 ofthe proximal end side of the proximal end side marker 22B is alignedwith the position of the boundary of the proximal end side of theinflatable region 33. In this case, the user can correctly determine theinflatable region 33 when the balloon 3 is inflated, using the markers22A and 22B. Further, the hard portion 42 is disposed so as tocorrespond to the inflatable region 33 identified by the markers 22A and22B. Thus, the user can easily ascertain that the hard portion 42 of thelinear member 4 is acting appropriately on the blood vessel at theinflatable region 33 identified by the markers 22A and 22B.

The proximal end side leg portion 31 of the balloon 3 is connected tothe outer tube 21 further toward the distal end side than the proximalend position M2. The proximal end position M2 corresponds to theposition at which the end portion on the proximal end side of the linearmember 4 is connected to the outer tube 21 via the mounting member 21A.Thus, the balloon catheter 10 can cause the linear member 4 to beseparated from the end portion on the proximal end side of the balloon3. In this case, the end portion on the proximal end side of the linearmember 4 is strongly fixed to the outer tube 21. Further, the ballooncatheter 10 can suppress an impact on the proximal end side leg portion31 of the balloon 3 caused by tension acting on the linear member 4.

The linear member 4 is formed of the synthetic resin. In this case, thelinear member 4 that includes the flexible portion 41 and the hardportion 42 can easily be manufactured by injection molding, extrusionmolding or the like.

Second Embodiment

A balloon catheter 20 according to a second embodiment of the presentdisclosure will be explained with reference to FIG. 9. Points in whichthe second embodiment differs from the first embodiment are as follows:

-   -   The mounting member 21A (refer to FIG. 2 and the like) is not        mounted on the outer tube 21, and    -   The end portion on the proximal end side of the linear member 4        is connected further toward the proximal end side than the        center in the extending direction of the proximal end side leg        portion 31 of the balloon 3.

Hereinafter, where the configuration is the same as that of the firstembodiment, the same reference numerals are assigned and an explanationthereof is omitted.

As shown in FIG. 9, the end portion on the proximal end side of thelinear member 4 is connected, by thermal welding, further toward theproximal end side than the center in the extending direction of theouter peripheral surface of the proximal end side leg portion 31 of theballoon 3. The proximal end position M2 that shows the position at whichthe end portion on the proximal end side of the linear member 4 isconnected corresponds to a position, of the proximal end side legportion 31 of the balloon 3, which is located further toward theproximal end side than the center in the extending direction.

Main Operations and Effects of Second Embodiment

In the balloon catheter 20 according to the second embodiment, thelinear member 4 can be fixed to the outer tube 21 without needing themounting member 21A. Thus, the costs of the balloon catheter 10 can bereduced. Further, in comparison to a case in which the linear member 4is connected directly to the outer tube 21, the linear member 4 can bereliably connected to the outer tube 21 by connecting the linear member4 to the outer tube 21 via the balloon 3.

Third Embodiment

A balloon catheter 30 according to a third embodiment of the presentdisclosure will be explained with reference to FIG. 10 and FIG. 11. Apoint in which the third embodiment differs from the second embodimentis that a linear member 6 is provided in place of the linear member 4.Hereinafter, where the configuration is the same as that of the firstembodiment and the second embodiment, the same reference numerals areassigned and an explanation thereof is omitted.

As shown in FIG. 10, the linear member 6 includes a flexible portion 61,and a hard portion 62. The end portion on the proximal end side of theflexible portion 61 is connected to the outer peripheral surface of theproximal end side leg portion 31 of the balloon 3, at the proximal endposition M2. The hard portion 62 includes a first portion 621 and asecond portion 622. The first portion 621 is adjacent to the distal endside of the flexible portion 61. The second portion 622 is adjacent tothe distal end side of the first portion 621. The end portion on thedistal end side of the second portion 622 is connected to the outerperipheral surface of the distal end side leg portion 35 of the balloon3, at the distal end position M1. The flexible portion 61, the firstportion 621 of the hard portion 62, and the second portion 622 of thehard portion 62 are disposed side by side in that order from theproximal end toward the distal end along the extending direction.

The flexible portion 61 corresponds to the first portion 411 (refer toFIG. 8) of the flexible portion 41 according to the first embodiment.The first portion 621 of the hard portion 62 corresponds to thelaminated portion (refer to FIG. 8) according to the first embodiment,in which the second portion 412 of the flexible portion 41 and the hardportion 42 are laminated. The second portion 622 of the hard portion 62corresponds to the third portion 413 (refer to FIG. 8) of the flexibleportion 41 according to the first embodiment. The shape of each of theportions is the same. The material of the flexible portion 61 is thesame as the material of the flexible portion 41 according to the firstembodiment. The material of the hard portion 62 is the same as thematerial of the hard portion 42 according to the first embodiment.

FIG. 11 shows cross sections of the linear member 6 at each of a lineA2-A2, a line B2-B2, and a line C2-C2. The shape of the cross section ofthe flexible portion 61 is a trapezoid shape. An inner portion 61A andan outer portion 61B respectively correspond to the inner portion 411Aand the outer portion 411B (refer to FIG. 8) of the flexible portion 41.A length between the inner portion 61A and the outer portion 61B of theflexible portion 61, namely, a thickness R21 of the flexible portion 61,is the same as the thickness R11 in the linear member 4. The shape ofthe cross section of the first portion 621 of the hard portion 62 is anequilateral triangle shape. An inner portion 621A and an outer portion621B respectively correspond to the inner portion 412A and the outerportion 42B (refer to FIG. 8) of the flexible portion 41. A lengthbetween the inner portion 621A and the outer portion 621B, namely, athickness R22 of the first portion 621 of the hard portion 62, is thesame as the thickness R12 in the linear member 4. The shape of the crosssection of the second portion 622 of the hard portion 62 is a trapezoidshape. An inner portion 622A and an outer portion 622B respectivelycorrespond to the inner portion 413A and the outer portion 413B (referto FIG. 8) of the flexible portion 41. A length between the innerportion 622A and the outer portion 622B of the hard portion 62, namely,a thickness R23 of the second portion 622, is the same as the thicknessR13 in the linear member 4. A distal end surface 62S and a proximal endsurface 62K respectively correspond to the distal end surface 42S andthe proximal end surface 42K (refer to FIG. 8) of the hard portion 42. Afirst direction D21 and a second direction D22 respectively correspondto the first direction D11 and the second direction D12 (refer to FIG.8). A first angle θ21 and a second angle θ22 respectively correspond tothe first angle θ11 and the second angle θ12 (refer to FIG. 8). Thepreferable five degrees of the first angle θ21 is smaller than thepreferable sixteen degrees of the second angle θ22.

In accordance with the inflation of the balloon 3, the first portion 621of the hard portion 62 of the linear member 6 tries to move away fromthe protruding portion 225 of the inner tube 22. At this time, theflexible portion 61 of the linear member 6 elastically deforms so as toextend along the extending direction. Thus, the first portion 621 of thehard portion 62 easily separates from the protruding portion 225 of theinner tube 22. The outer portion 621B of the first portion 621 of thehard portion 62 protrudes to the outside with respect to the balloon 3.

Main Operations and Effects of Third Embodiment

In the balloon catheter 30 according to the third embodiment, the firstportion 621 of the hard portion 62 is disposed in a portion, of thelinear member 6, that is aligned with the position, in the extendingdirection, of the inflatable region 33 of the balloon 3 in the inflatedstate. When the balloon 3 is inflated, the flexible portion 61 of thelinear member 6 elastically deforms so as to extend along the extendingdirection. In this way, the first portion 621 of the hard portion 62moves away from the protruding portion 225 of the inner tube 22. Theouter portion 621B is disposed on the opposite side to the inner portion621A that faces the outer peripheral surface of the balloon 3. Thus,with the balloon catheter 30, when the balloon 3 is inflated in thestate in which the balloon 3 is disposed at the constricted portion ofthe blood vessel, the hard portion 62 acts appropriately on theconstricted portion of the blood vessel.

In the balloon catheter 30, the first portion 621 of the hard portion 62is provided from the inside, which faces the inflatable region 33 of theballoon 3, to the outside. Thus, even if the linear member 6 rotateswith respect to the balloon 3, the linear member 6 can orient the hardportion 62 toward the outside. Further, the hard portion 62 is disposednot only at the portion corresponding to the inflatable region 33 of theballoon 3, but also at the portion corresponding further toward thedistal end side than the inflatable region 33. Thus, the ballooncatheter 30 can cause the second portion 622 of the hard portion 62 toact on the constricted portion of the blood vessel further toward thedistal end side than the inflatable region 33, when the balloon 3 isinflated in the state in which the balloon 3 is disposed at theconstricted portion of the blood vessel.

In the linear member 6, the flexible portion 61 and the hard portion 62are adjacent in the extending direction. Thus, the linear member 6 canbe easily manufactured by connecting the respective end portions of theflexible portion 61 and the hard portion 62 in the extending direction.

Fourth Embodiment

A balloon catheter 40 according to a fourth embodiment of the presentdisclosure will be explained with reference to FIG. 12 and FIG. 13. Apoint in which the fourth embodiment differs from the second embodimentis that a linear member 7 is provided in place of the linear member 4.Hereinafter, where the configuration is the same as that of the firstembodiment to the third embodiment, the same reference numerals areassigned and an explanation thereof is omitted.

As shown in FIG. 12, the linear member 7 includes a hard portion 71 anda flexible portion 72. The hard portion 71 includes a first portion 711and a second portion 712. The end portion on the proximal end side ofthe first portion 711 is connected to the outer peripheral surface ofthe proximal end side leg portion 31 of the balloon 3, at the proximalend position M2. The second portion 712 is adjacent to the distal endside of the first portion 711. The flexible portion 72 is adjacent tothe distal end side of the second portion 712 of the hard portion 71.The end portion on the distal end side of the flexible portion 72 isconnected to the outer peripheral surface of the distal end side legportion 35 of the balloon 3, at the distal end position M1. The firstportion 711 of the hard portion 71, the second portion 712 of the hardportion 71, and the flexible portion 72 are disposed side by side inthat order from the proximal end toward the distal end along theextending direction.

The first portion 711 of the hard portion 71 corresponds to the firstportion 411 (refer to FIG. 8) of the flexible portion 41 according tothe first embodiment. The second portion 712 of the hard portion 71corresponds to the laminated portion (refer to FIG. 8) according to thefirst embodiment, in which the second portion 412 of the flexibleportion 41 and the hard portion 42 are laminated. The flexible portion72 corresponds to the third portion 413 (refer to FIG. 8) of theflexible portion 41 according to the first embodiment. The shape of eachof the portions is the same. The material of the flexible portion 72 isthe same as the material of the flexible portion 41 according to thefirst embodiment. The material of the hard portion 71 is the same as thematerial of the hard portion 42 according to the first embodiment.

FIG. 13 shows cross sections of the linear member 7 at each of a lineA3-A3, a line B3-B3, and a line C3-C3. The cross-sectional shape of thefirst portion 711 of the hard portion 71 is a trapezoid shape. An innerportion 711A and an outer portion 711B of the first portion 711respectively correspond to the inner portion 411A and the outer portion411B (refer to FIG. 8) of the flexible portion 41. A length between theinner portion 711A and the outer portion 711B, namely, a thickness R31of the first portion 711, is the same as the thickness R11 in the linearmember 4. The shape of the cross section of the second portion 712 ofthe hard portion 71 is an equilateral triangle shape. An inner portion712A and an outer portion 712B of the second portion 712 respectivelycorrespond to the inner portion 412A and the outer portion 42B (refer toFIG. 8) of the flexible portion 41. A length between the inner portion712A and the outer portion 712B, namely, a thickness R32 of the secondportion 712, is the same as the thickness R12 in the linear member 4.The shape of the cross section of the flexible portion 72 is a trapezoidshape. An inner portion 72A and an outer portion 72B of the flexibleportion 72 respectively correspond to the inner portion 413A and theouter portion 413B (refer to FIG. 8) of the flexible portion 41. Alength between the inner portion 72A and the outer portion 72B, namely,a thickness R33 of the flexible portion 72, is the same as the thicknessR13 in the linear member 4. A distal end surface 72S and a proximal endsurface 72K respectively correspond to the distal end surface 42S andthe proximal end surface 42K (refer to FIG. 8) of the hard portion 42. Afirst direction D31 and a second direction D32 respectively correspondto the first direction D11 and the second direction D12 (refer to FIG.8). A first angle θ31 and a second angle θ32 respectively correspond tothe first angle θ11 and the second angle θ12 (refer to FIG. 8). Thepreferable five degrees of the first angle θ31 is smaller than thepreferable sixteen degrees of the second angle θ32.

In accordance with the inflation of the balloon 3, the second portion712 of the hard portion 71 of the linear member 7 tries to move awayfrom the protruding portion 225 of the inner tube 22. At this time, theflexible portion 72 of the linear member 7 elastically deforms so as toextend along the extending direction. Thus, the second portion 712 ofthe hard portion 71 easily separates from the protruding portion 225 ofthe inner tube 22. The outer portion 712B of the second portion 712 ofthe hard portion 71 protrudes to the outside with respect to the balloon3.

Main Operations and Effects of Fourth Embodiment

In the balloon catheter 40 according to the fourth embodiment, thesecond portion 712 of the hard portion 71 is disposed in a portion, ofthe linear member 7, that is aligned with the position, in the extendingdirection, of the inflatable region 33 of the balloon 3 in the inflatedstate. When the balloon 3 is inflated, the flexible portion 72 of thelinear member 7 elastically deforms so as to extend along the extendingdirection. In this way, the second portion 712 of the hard portion 71moves away from the protruding portion 225 of the inner tube 22. Theouter portion 712B is disposed on the opposite side to the inner portion712A that faces the outer peripheral surface of the balloon 3. Thus,with the balloon catheter 40, when the balloon 3 is inflated in thestate in which the balloon 3 is disposed at the constricted portion ofthe blood vessel, the hard portion 71 acts appropriately on theconstricted portion of the blood vessel.

In the balloon catheter 40, the second portion 712 of the hard portion71 is provided from the inside, which faces the inflatable region 33 ofthe balloon 3, to the outside. Thus, even if the linear member 7 rotateswith respect to the balloon 3, the linear member 7 can orient the hardportion 71 toward the outside. Further, the hard portion 71 is disposednot only at the portion corresponding to the inflatable region 33 of theballoon 3, but also at the portion corresponding further toward theproximal end side than the inflatable region 33. Thus, the ballooncatheter 40 can cause the first portion 711 of the hard portion 71 toact on the constricted portion of the blood vessel further toward theproximal end side than the inflatable region 33, when the balloon 3 isinflated in the state in which the balloon 3 is disposed at theconstricted portion of the blood vessel.

In the linear member 7, the hard portion 71 and the flexible portion 72are adjacent in the extending direction. Thus, the linear member 7 canbe easily manufactured by connecting the respective end portions of thehard portion 71 and the flexible portion 72 in the extending direction.

Fifth Embodiment

A balloon catheter 50 according to a fifth embodiment of the presentdisclosure will be explained with reference to FIG. 14 and FIG. 15. Apoint in which the fifth embodiment differs from the second embodimentis that a linear member 8 is provided in place of the linear member 4.Hereinafter, where the configuration is the same as that of the firstembodiment to the fourth embodiment, the same reference numerals areassigned and an explanation thereof is omitted.

As shown in FIG. 14, the linear member 8 includes flexible portions 81and 83, and a hard portion 82. The end portion on the proximal end sideof the flexible portion 81 is connected to the outer peripheral surfaceof the proximal end side leg portion 31 of the balloon 3, at theproximal end position M2. The hard portion 82 is adjacent to the distalend side of the flexible portion 81. The flexible portion 83 is adjacentto the distal end side of the hard portion 82. The end portion on thedistal end side of the flexible portion 83 is connected to the outerperipheral surface of the distal end side leg portion 35 of the balloon3, at the distal end position M1. The flexible portion 81, the hardportion 82, and the flexible portion 83 are disposed side by side inthat order from the proximal end toward the distal end along theextending direction.

The flexible portion 81 corresponds to the first portion 411 (refer toFIG. 8) of the flexible portion 41 according to the first embodiment.The hard portion 82 corresponds to the laminated portion (refer to FIG.8) according to the first embodiment, in which the second portion 412 ofthe flexible portion 41 and the hard portion 42 are laminated. Theflexible portion 83 corresponds to the third portion 413 (refer to FIG.8) of the flexible portion 41 according to the first embodiment. Theshape of each of the portions is the same. The material of the flexibleportions 81 and 83 is the same as the material of the flexible portion41 according to the first embodiment. The material of the hard portion82 is the same as the material of the hard portion 42 according to thefirst embodiment.

FIG. 15 shows cross sections of the linear member 8 at each of a lineA4-A4, a line B4-B4, and a line C4-C4. The cross-sectional shape of theflexible portion 81 is a trapezoid shape. An inner portion 81A and anouter portion 81B of the flexible portion 81 respectively correspond tothe inner portion 411A and the outer portion 411B (refer to FIG. 8) ofthe flexible portion 41. A length between the inner portion 81A and theouter portion 81B, namely, a thickness R41 of the flexible portion 81,is the same as the thickness R11 in the linear member 4. The shape ofthe cross section of the hard portion 82 is an equilateral triangleshape. An inner portion 82A and an outer portion 82B of the hard portion82 respectively correspond to the inner portion 412A and the outerportion 42B (refer to FIG. 8) of the flexible portion 41. A lengthbetween the inner portion 82A and the outer portion 82B, namely, athickness R42 of the hard portion 82, is the same as the thickness R12in the linear member 4. The shape of the cross section of the flexibleportion 83 is a trapezoid shape. An inner portion 83A and an outerportion 83B of the flexible portion 83 respectively correspond to theinner portion 413A and the outer portion 413B (refer to FIG. 8) of theflexible portion 41. A length between the inner portion 83A and theouter portion 83B, namely, a thickness R43 of the flexible portion 83,is the same as the thickness R13 in the linear member 4. A distal endsurface 82S and a proximal end surface 82K respectively correspond tothe distal end surface 42S and the proximal end surface 42K (refer toFIG. 8) of the hard portion 42. A first direction D41 and a seconddirection D42 respectively correspond to the first direction D11 and thesecond direction D12 (refer to FIG. 8). A first angle θ41 and a secondangle θ42 respectively correspond to the first angle θ11 and the secondangle θ12 (refer to FIG. 8). The preferable five degrees of the firstangle θ41 is smaller than the preferable sixteen degrees of the secondangle θ42.

In accordance with the inflation of the balloon 3, the hard portion 82of the linear member 8 tries to move away from the protruding portion225 of the inner tube 22. At this time, the flexible portions 81 and 83of the linear member 8 elastically deform so as to extend along theextending direction. Thus, the hard portion 82 easily separates from theprotruding portion 225 of the inner tube 22. The outer portion 82B ofthe hard portion 82 protrudes to the outside with respect to the balloon3.

Main Operations and Effects of Fifth Embodiment

In the balloon catheter 50 according to the fifth embodiment, the hardportion 82 is disposed in a portion, of the linear member 8, that isaligned with the position, in the extending direction, of the inflatableregion 33 of the balloon 3 in the inflated state. When the balloon 3 isinflated, the flexible portions 81 and 83 of the linear member 8elastically deform so as to extend along the extending direction. Inthis way, the hard portion 82 moves away from the protruding portion 225of the inner tube 22. The outer portion 82B is disposed on the oppositeside to the inner portion 82A that faces the outer peripheral surface ofthe balloon 3. Thus, when the balloon 3 is inflated in the state inwhich the balloon 3 is disposed at the constricted portion of the bloodvessel, the hard portion 82 acts appropriately on the constrictedportion of the blood vessel.

In the balloon catheter 50, the flexible portions 81 and 83 are providedon the distal end side and the proximal end side of the hard portion 82.Thus, the linear member 8 easily extends in the extending direction whenthe balloon 3 is inflated. As a result, the balloon catheter 50 caneasily cause the hard portion 82 to separate from the protruding portion225 of the inner tube 22.

In the linear member 8, the flexible portion 81, the hard portion 82,and the flexible portion 83 are adjacent to each other in the extendingdirection. Thus, the linear member 8 can be easily manufactured byconnecting the respective end portions in the extending direction of theflexible portions 81 and 81, and the hard portion 82.

Sixth Embodiment

A balloon catheter 90 according to a sixth embodiment will be explainedwith reference to FIG. 16 to FIG. 19. Points in which the sixthembodiment differs from the second embodiment are as follows:

-   -   A linear member 9 is provided in place of the linear member 4,        and    -   The linear member 9 is bonded to the balloon 3 across the whole        length of the linear member 9 in the extending direction.

Hereinafter, where the configuration is the same as that of the firstembodiment to the fifth embodiment, the same reference numerals areassigned and an explanation thereof is omitted.

Linear Member 9

The linear member 9 will be explained with reference to FIG. 16 to FIG.19. Linear members 9A, 9B, and 9C respectively correspond to the linearmembers 4A, 4B, and 4C according to the second embodiment. As shown inFIG. 16 to FIG. 18, the linear member 9 is bonded to the outerperipheral surface of the balloon 3 across the whole length of thelinear member 9 from the proximal end position M2 to the distal endposition M1. For example, the linear member 9 is bonded to the outerperipheral surface of the balloon 3 using thermal welding. However, thelinear member 9 may be bonded to the outer peripheral surface of theballoon 3 using another method, such as adhesive or the like. As shownin FIG. 17, when the balloon 3 is in the inflated state, the linearmembers 9A, 9B, and 9C extend in straight lines in the extendingdirection, at positions respectively dividing the balloon 3 into threeapproximately equal parts in the circumferential direction. At thattime, a force in a direction to try and elongate the linear member 9 inthe extending direction (hereinafter referred to as a “force in anelongation direction”) acts on the linear member 9. In contrast to this,when the balloon 3 is in the deflated state, the force in the elongationdirection does not act on the linear member 9.

As shown in FIG. 16 and FIG. 18, the linear member 9 includes a flexibleportion 91 and a hard portion 92. The flexible portion 91 extendsbetween the proximal end position M2 and the distal end position M1. Theflexible portion 91 includes a first portion 911, a second portion 912,and a third portion 913. The first portion 911, the second portion 912,and the third portion 913 respectively correspond to sections of theflexible portion 91 that is divided into three in the extendingdirection. The first portion 911 is bonded to the outer peripheralsurfaces of the proximal end side leg portion 31 and the proximal endside cone region 32 of the balloon 3. The second portion 912 is adjacentto the distal end side of the first portion 911. The second portion 912is bonded to the outer peripheral surface of the inflatable region 33 ofthe balloon 3. The third portion 913 is adjacent to the distal end sideof the second portion 912. The third portion 913 is bonded to the outerperipheral surfaces of the distal end side cone region 34 and the distalend side leg portion 35 of the balloon 3. The hard portion 92 islaminated to a portion, of the second portion 912 of the flexibleportion 91, on the opposite side to the portion bonded to the balloon 3.

FIG. 19 shows cross sections of the linear member 9 at each of a lineA5-A5, a line B5-B5, and a line C5-C5 in a state in which the force inthe elongation direction is not acting on the linear member 9. Thecross-sectional shape of the linear member 9 is a trapezoid shape or anequilateral triangle shape. Specifically, it is as described below.

The shape of the cross section of the flexible portion 91 (the firstportion 911 to the third portion 913) is the trapezoid shape.Hereinafter, of the first portion 911 of the flexible portion 91, aportion bonded to the balloon 3 (refer to FIG. 16) is referred to as an“inner portion 911A.” Of the first portion 911, a portion on theopposite side to the inner portion 911A is referred to as an “outerportion 911B.” Of the second portion 912 of the flexible portion 91, aportion bonded to the balloon 3 is referred to as an “inner portion912A.” Of the second portion 912, a portion on the opposite side to theinner portion 912A is referred to as a “boundary 912B.” Of the thirdportion 913 of the flexible portion 91, a portion bonded to the balloon3 is referred to as an “inner portion 913A.” Of the third portion 913, aportion on the opposite side to the inner portion 913A is referred to asan “outer portion 913B.” The inner portions 911A, 912A, and 913Arespectively correspond to the lower base of the trapezoid that is thecross-sectional shape. The outer portions 911B and 913B, and theboundary 912B respectively correspond to the upper base of the trapezoidthat is the cross-sectional shape.

The shape of the cross section of the hard portion 92 is an equilateraltriangle shape having the boundary 912B of the second portion 912 as oneside. The hard portion 92 protrudes to the outside from the boundary912B of the second portion 912 of the flexible portion 91. Hereinafter,an end portion on the outside of the hard portion 92 is referred to asan “outer portion 92B.” The outer portion 92B corresponds to an apex ofthe equilateral triangle shape, and thus is peaked.

A length between the inner portion 911A and the outer portion 911B ofthe first portion 911, namely, a thickness of a portion of the flexibleportion 91 further toward the proximal end side than the hard portion92, is denoted as a thickness R51. A length between the inner portion912A and the boundary 912B of the second portion 912, namely, athickness of a portion of the flexible portion 91 that overlaps with thehard portion 92 in the extending direction, is denoted as R52. A lengthbetween the inner portion 913A and the outer portion 913B of the thirdportion 913, namely, a thickness of a portion of the flexible portion 91further toward the distal end side than the hard portion 92, is denotedas R53. In this case, the thicknesses R51, R52, and R53 are equal.

An end surface on the distal end side of the hard portion 92 is referredto a “distal end surface 92S.” A virtual first direction D51 is definedthat extends toward the outside along the distal end surface 92S of thehard portion 92. The first direction D51 is inclined toward the proximalend side with respect to the direction orthogonal to the extendingdirection. An end surface on the proximal end side of the hard portion92 is referred to as a “proximal end surface 92K.” A virtual seconddirection D52 is defined that extends toward the outside along theproximal end surface 92K of the hard portion 92. The second directionD52 is inclined toward the distal end side with respect to the directionorthogonal to the extending direction. An acute angle, of angles formedbetween the first direction D51 and the extending direction, is definedas a first angle θ51. The first angle 051 is an angle between 4 to 13degrees, for example. The first angle θ51 is preferably 5 degrees. Anacute angle, of angles formed between the second direction D52 and theextending direction is defined as a second angle θ52. The second angleθ52 is an angle between 5 to 16 degrees, for example. The second angleθ52 is preferably 16 degrees. The preferable five degrees of the firstangle θ51 is smaller than the preferable sixteen degrees of the secondangle θ52.

As shown in FIG. 18, a position of a boundary on the distal end side ofthe second portion 912 of the flexible portion 91, in other words, aposition of a boundary between the second portion 912 and the thirdportion 913, is aligned, in the extending direction, with the positionP11 of the end portion on the distal end side of the marker 22A. Aposition of a boundary on the proximal end side of the second portion912 of the flexible portion 91, in other words, a position of a boundarybetween the first portion 911 and the second portion 912, is aligned, inthe extending direction, with the position P21 of the end portion on theproximal end side of the marker 22B. Note that the hard portion 92 ofthe linear member 9 is laminated on the second portion 912 of theflexible portion 91. Thus, the inflatable region 33 of the balloon 3,the second portion 912 of the flexible portion 91, and the hard portion92 are all disposed in the same position in the extending direction.

As shown in FIG. 19, two notches 51, which extend toward the inside inthe radial direction from the outer portion 92B of the hard portion 92,are formed in the linear member 9. Each of the two notches 51 is formedby cutting out a part of the linear member 9. A cross-sectional shape ofeach of the notches 51 is a wedge shape. The two notches 51 are disposedside by side at an equal interval in the extending direction.

Each of the notches 51 includes surfaces 51A and 51B that face eachother in the extending direction. When the balloon 3 is not in theinflated state, namely, in the state in which the force in theelongation direction is not acting on the linear member 9, a directionthat extends to the outside along the surface 51A is inclined toward theproximal end side with respect to the direction orthogonal to theextending direction. A direction that extends to the outside along thesurface 51B is inclined toward the distal end side with respect to thedirection orthogonal to the extending direction. The surfaces 51A and51B are disposed with an interval therebetween in the extendingdirection. A gap is formed between the surfaces 51A and 51B. Thesurfaces 51A and 51B are connected by respective inside end portionsthereof. The end portions that connect the surfaces 51A and 51B are, inother words, an end portion (hereinafter referred to as a “bottomportion”) 51C of the inside of the notch 51. The bottom portion 51C ispositioned further to the inside, in the radial direction, than theboundary 912B that represents the boundary between the second portion912 of the flexible portion 91 and the hard portion 92.

When the balloon 3 inflates as a result of the compressed fluid beingsupplied from the hub 5, the force in the elongation direction acts onthe first portion 911 and the third portion 913 of the flexible portion91 of the linear member 9. As a result, the first portion 911 and thethird portion 913 elastically deform so as to extend along the extendingdirection. Further, of the linear member 9, the force in the extendingdirection also acts on the section at which the second portion 912 ofthe flexible portion 91 and the hard portion 92 are laminated. Here, incomparison to the flexible portion 91, the hard portion 92 does noteasily extend. As a result of the second portion 912 of the flexibleportion 91 elastically deforming due to the force in the extendingdirection, the respective surfaces 51A and 51B of the plurality ofnotches 51 separate from each other in the extending direction. As aresult, the elastic deformation of the second portion 912 of theflexible portion 91 is not easily suppressed by the hard portion 92.Thus, of the linear member 9, even the section in which the secondportion 912 of the flexible portion 91 and the hard portion 92 arelaminated elastically deforms so as to extend in the extending directionin accordance with the inflation of the balloon 3. As a result of theabove, the linear member 9 follows the inflation of the balloon 3 andextends in the extending direction across the whole length of the linearmember 9 in the extending direction.

Meanwhile, when the balloon 3 deflates as a result of the compressedfluid being discharged from the balloon 3 in the inflated state, theflexible portion 91 of the linear member 9 that is extended in theextending direction contracts due to a restoring force. The surfaces 51Aand 51B of the notches 51 of the hard portion 92 of the linear member 9approach each other with a space therebetween in the extendingdirection. The linear member 9A is covered from the outside by the pleat3A, the linear member 9B is covered from the outside by the pleat 3B,and the linear member 9C is covered from the outside by the pleat 3C.

Main Operations and Effects of Sixth Embodiment

In the balloon catheter 90, when the balloon 3 is inflated, the forcethat tries to elongate acts on the linear member 9. If the linear member9 does not extend well even when this force is acting, the linear member9 cannot follow the inflation of the balloon 3 and there is apossibility that the linear member 9 may break away from the balloon 3.Further, there is a case in which the inflation of the balloon 3 isobstructed by the linear member 9. Thus, it is preferable that theextendability of the linear member 9 be high. On the other hand, inorder to cause the linear member 9 to act appropriately on the bloodvessel when the balloon 3 is inflated, it is preferable that thehardness of the linear member 9 be harder.

In response to this, in the balloon catheter 90, when the balloon 3 isinflated, the outer portion 92B of the hard portion 92 of the linearmember 9 protrudes to the outside with respect to the balloon 3. Thehardness of the hard portion 92 is harder than the flexible portion 91.Thus, the linear member 9 can cause the hard portion 92 to actappropriately on the blood vessel when the balloon 3 is inflated. Forexample, since the outer portion 92B of the hard portion 92 is peaked,the hard portion 92 easily bites into the lesioned part (not shown inthe drawings) of the blood vessel. As a result, in a state in which thelinear member 9 causes the balloon 3 to be in a state of not easilyslipping with respect to the lesioned part of the blood vessel, thelesioned part can be expanded from inside by the inflation of theballoon 3.

The flexible portion 91 of the linear member 9 can extend. Thus, whenthe linear member 9 tries to extend in accordance with the inflation ofthe balloon 3, the first portion 911 and the third portion 913, of theflexible portion 91, on which the hard portion 92 is not laminatedextend in a favorable manner, and follow the balloon 3. Further, the twonotches 51 are formed in the linear member 9. Thus, when the secondportion 912 of the flexible portion 91 tries to extend in accordancewith the inflation of the balloon 3, the surfaces 51A and 51B of each ofthe notches 51 separate from each other, thus suppressing the hardportion 92 from obstructing the extending of the second portion 912 ofthe flexible portion 91. As a result, the linear member 9 can extendappropriately across the whole length of the linear member 9 inaccordance with the inflation of the balloon 3, and can follow theinflation of the balloon 3. Thus, the balloon catheter 90 can inhibitthe linear member 9 from breaking away from the balloon 3 when theballoon 3 is inflated, or inhibit the linear member 9 from obstructingthe inflation of the balloon 3.

The bottom portion 51C of each of the notches 51 is positioned furtherto the inside, in the radial direction, than the boundary 912B betweenthe second portion 912 of the flexible portion 91 and the hard portion92. In this case, the hard portion 92 is divided into three by the twonotches 51. Thus, the linear member 9 can appropriately suppress thehard portion 92 from obstructing the extending of the second portion 912of the flexible portion 91. As a result, the balloon catheter 90 caneven more appropriately inhibit the linear member 9 from breaking awayfrom the balloon 3 when the balloon 3 is inflated, or inhibit the linearmember 9 from obstructing the inflation of the balloon 3.

The surfaces 51A and 51B of each of the two notches 51 are disposed soas to be separated from each other in the extending direction. In thiscase, the linear member 9 can easily bend in the direction orthogonal tothe extending direction at the section in which the notches 51 areformed. As a result, when the balloon 3 bends in the directionorthogonal to the extending direction, the balloon catheter 90 can causethe linear member 9 to follow the balloon 3 and bend. Thus, the ballooncatheter 90 can suppress the linear member 9 from breaking away from theballoon 3 when the balloon 3 bends.

The linear member 9 is bonded to the outer peripheral surface of theballoon 3 between the distal end position M1 and the proximal endposition M2. As a result, the linear member 9 is held in a fixedposition with respect to the balloon 3. Thus, the balloon catheter 90can cause the linear member 9 to act on the blood vessel when theballoon 3 is inflated, while the linear member 9 is held in a correctposition with respect to the balloon 3. Further, by directly bonding thelinear member 9 to the balloon 3, the balloon catheter 90 can inhibitthe position of the linear member 9 with respect to the balloon 3 fromchanging in accordance with the inflation of the balloon 3.

The first direction D51, which extends to the outside along the distalend surface 92S that is the end portion of the hard portion 92 on thedistal end side, is inclined toward the proximal end side. In this case,when the balloon catheter 90 moves inside the blood vessel in the courseof the user causing the balloon 3 to approach the constricted portion ofthe blood vessel, the linear member 9 can be inhibited from catching onthe inner wall of the blood vessel. Thus, the user can smoothly move theballoon 3 as far as the constricted portion of the blood vessel.Further, the second direction D52, which extends to the outside alongthe proximal end surface 92K that is the end portion of the hard portion92 on the proximal end side, is inclined toward the distal end side. Inthis case, when the balloon catheter 90 moves inside the blood vessel inthe course of the user pulling the balloon catheter 90 out from theblood vessel, the linear member 9 can be inhibited from catching on theinner wall of the blood vessel. Thus, the user can easily pull theballoon catheter 90 out from the blood vessel.

The linear member 9 is formed of a synthetic resin. In this case, thelinear member 9 that includes the flexible portion 91 and the hardportion 92 can be easily manufactured by injection molding, extrusionmolding or the like.

Seventh Embodiment and Eighth Embodiment

A seventh embodiment and an eighth embodiment will be explained withreference to FIG. 20 and FIG. 21. In the seventh embodiment, in place ofthe notches 51 of the sixth embodiment, notches 52 (refer to FIG. 20)are formed in the linear member 9. In the eighth embodiment, in place ofthe notches 51 of the sixth embodiment, notches 53 (refer to FIG. 21)are formed in the linear member 9. Other parts of the configuration arethe same as those of the sixth embodiment. Hereinafter, where theconfiguration is the same as that of the above-described embodiments,the same reference numerals are assigned and an explanation thereof isomitted.

As shown in FIG. 20, in the seventh embodiment, the notch 52 includessurfaces 52A and 52B. The end portion on the inside of the notch 52 isreferred to as a “bottom portion 52C.” The surfaces 52A and 52B, and thebottom portion 52C respectively correspond to the surfaces 51A and 51B,and the bottom portion 51C of the notch 51 of the sixth embodiment. Inthe notch 52, a position of the bottom portion 52C in the radialdirection is different to that of the notch 51. In the notch 52, thebottom portion 52C is positioned in substantially the same position asthe boundary 912B between the second portion 912 of the flexible portion91 and the hard portion 92. In this case, similarly to the sixthembodiment, the hard portion 92 is divided into three in the extendingdirection by two of the notches 52. As a result, the linear member 9 canappropriately suppress the extending of the second portion 912 of theflexible portion 91 from being obstructed by the hard portion 92. Thus,similarly to the sixth embodiment, the balloon catheter 90 can even moreappropriately inhibit the linear member 9 from breaking away from theballoon 3 when the balloon 3 is inflated, or inhibit the linear member 9from obstructing the inflation of the balloon 3. In addition, incontrast to the sixth embodiment, a part of the notch 52 is not formedin the flexible portion 91. Therefore, in comparison to the case inwhich the part of the notch 51 is formed in the second portion 912 ofthe flexible portion 91 as in the sixth embodiment, the strength of thesecond portion 912 of the flexible portion 91 is maintained whenextending.

As shown in FIG. 21, in the eighth embodiment, the notch 53 includessurfaces 53A and 53B. The end portion on the inside of the notch 53 isreferred to as a “bottom portion 53C.” The surfaces 53A and 53B, and thebottom portion 53C respectively correspond to the surfaces 51A and 51B,and the bottom portion 51C of the notch 51 of the above-describedembodiment. In the notch 53, a position of the bottom portion 53C in theradial direction is different to that of the notches 51 and 52. In thenotch 53, the bottom portion 53C is positioned further to the outsidethan the boundary 912B between the second portion 912 of the flexibleportion 91 and the hard portion 92.

When the notch 53 is formed in the linear member 9, in contrast to thesixth embodiment and the seventh embodiment, the hard portion 92 is notdivided in the extending direction by the notch 53. However, of the hardportion 92, a portion further to the inside than the bottom portion 53Cof the notch 53 extends easily in the extending direction, compared to aportion in which the notch 53 is not formed. Therefore, of the linearmember 9, the portion in which the second portion 912 of the flexibleportion 91 and the hard portion 92 are laminated extends in theextending direction in accordance with the inflation of the balloon 3.Thus, similarly to the sixth embodiment and the seventh embodiment, theballoon catheter 90 can inhibit the linear member 9 from breaking awayfrom the balloon 3 when the balloon 3 is inflated, or inhibit the linearmember 9 from obstructing the inflation of the balloon 3.

The depth of the notch 53 is smaller than that of the notches 51 and 52,and therefore, the space between the surfaces 53A and 53B can beminimized when the surfaces 53A and 53B separate from each other inaccordance with the inflation of the balloon 3. As a result, an area ofthe outer portion 92B of the hard portion 92 can be made larger than inthe case of the sixth embodiment and the seventh embodiment. Note that,when the balloon 3 is inflated, the outer portion 92B of the hardportion 92 comes into contact with the blood vessel wall. Thus, sincethe balloon catheter 90 can increase the area of the portion (the outerportion 92B of the hard portion 92) of the linear member 9 that comesinto contact with the blood vessel wall, the balloon catheter 90 cancause the linear member 9 to act appropriately on the blood vessel whenthe balloon 3 is inflated.

Ninth Embodiment

A ninth embodiment will be explained with reference to FIG. 22. In theninth embodiment, incisions 54 are formed in place of the notches 51 ofthe sixth embodiment. Other parts of the configuration are the same asthose of the sixth to eighth embodiments. Hereinafter, where theconfiguration is the same as that of the above-described embodiments,the same reference numerals are assigned and an explanation thereof isomitted.

As shown in FIG. 22, the incision 54 extends to the inside along theradial direction, from the outer portion 92B of the hard portion 92. Theincision 54 includes surfaces 54A and 54B that face each other in theextending direction. An end portion (hereinafter referred to as a“bottom portion”) MC on the inside of each of the incisions 54 ispositioned further to the inside, in the radial direction, than theboundary 912B between the second portion 912 of the flexible portion 91and the hard portion 92.

When the compressed fluid is not supplied from the hub 5 and the balloon3 is not in the inflated state, the force in the elongation directiondoes not act on the linear member 9. In this case, as shown in FIG. 22,the surfaces 54A and 54B are in contact with each other. A gap is notformed between the surfaces 54A and 54B. On the other hand, when theballoon 3 is inflated as a result of the compressed fluid being suppliedfrom the hub 5, the force in the elongation direction acts on theportion, of the linear member 9, at which the second portion 912 of theflexible portion 91 and the hard portion 92 are laminated. The surfaces54A and 54B of the incision 54 separate from each other in the extendingdirection, as a result of the elastic deformation of the second portion912 of the flexible portion 91. The hard portion 92 is divided in theextending direction by the incisions 54. Thus, the elastic deformationof the second portion 912 of the flexible portion 91 is not easilysuppressed by the hard portion 92. As a result, the portion of thelinear member 9 at which the second portion 912 of the flexible portion91 and the hard portion 92 are laminated extends in the extendingdirection in accordance with the inflation of the balloon 3. Meanwhile,when the balloon 3 is deflated as a result of the compressed fluid beingdischarged from the balloon 3 in the inflated state, the flexibleportion 91 of the linear member 9 that is extended in the extendingdirection contracts due to the restoring force. The surfaces 54A and 54Bof the incision 54 of the hard portion 92 once more come into contactwith each other. The surfaces 54A and 54B return to the state in whichthe gap is not formed therebetween.

Main Operations and Effects of Ninth Embodiment

As described above, in the ninth embodiment, the surfaces 54A and 54B ofthe incision 54 are in contact with each other when the balloon 3 is notinflated and the gap between them is not formed. In this case, even whenthe surfaces 54A and 54B separate from each other as a result of theinflation of the balloon 3, the gap between the surfaces 54A and 54B canbe suppressed to a minimum Thus, the area of the outer portion 92B ofthe hard portion 92 of the linear member 9 can be made as large aspossible. As a result, since the balloon catheter 90 can make the areaof the portion (the outer portion 92B of the hard portion 92) of thelinear member 9 that comes into contact with the blood vessel wall aslarge as possible, the balloon catheter 90 can cause the linear member 9to act even more appropriately on the blood vessel when the balloon 3 isinflated.

It should be noted that, in the ninth embodiment, similarly to the caseof the notch 52 (refer to FIG. 20) of the seventh embodiment, the bottomportion 54C may be positioned in substantially the same position as theboundary 912B between the second portion 912 of the flexible portion 91and the hard portion 92. Further, in the ninth embodiment, similarly tothe case of the notch 53 (refer to FIG. 21) of the eighth embodiment,the bottom portion 54C may be positioned further to the outside than theboundary 912B between the second portion 912 of the flexible portion 91and the hard portion 92.

The notch 51 of the sixth embodiment, the notch 52 of the seventhembodiment, the notch 53 of the eighth embodiment, and the incision 54of the ninth embodiment may also be formed in the linear members 4, 6,7, and 8 of the balloon catheters 10, 20, 40, and 50 according to thefirst to fifth embodiments.

For example, a state of the linear member 4 will be explained when theballoon 3 inflates as a result of the compressed fluid being suppliedfrom the hub 5, in a case in which a plurality of the notches 51 areformed in the linear member 4 of the balloon catheter 10 according tothe first embodiment. In accordance with the inflation of the balloon 3,the hard portion 42 of the linear member 4 tries to move away from theprotruding portion 225 of the inner tube 22. At this time, the force inthe elongation direction acts on the first portion 411 and the thirdportion 413 of the flexible portion 41 of the linear member 4. As aresult, the first portion 411 and the third portion 413 elasticallydeform so as to extend in the extending direction. Thus, the hardportion 42 separates easily from the protruding portion 225 of the innertube 22. Further, the force in the extending direction also acts on thesection of the linear member 4 at which the second portion 412 of theflexible portion 41 and the hard portion 42 are laminated. Here, therespective surfaces 51A and 51B of the plurality of notches 51 of theflexible portion 41 separate from each other in the extending directionin accordance with the elastic deformation of the second portion 412 ofthe flexible portion 41 caused by the force in the extending direction.As a result, the elastic deformation of the second portion 412 of theflexible portion 41 is not easily suppressed by the hard portion 42.Therefore, the section of the linear member 4 at which the secondportion 412 of the flexible portion 41 and the hard portion 42 arelaminated also elastically deforms so as to extend in the extendingdirection in accordance with the inflation of the balloon 3. As a resultof the above, the linear member 4 extends in the extending directionover the whole length of the linear member 4 in the extending direction.

Meanwhile, when the balloon 3 deflates as a result of the compressedfluid being discharged from the balloon 3 in the inflated state, theflexible portion 41 of the linear member 4 that is extended in theextending direction contracts due to the restoring force. The surfaces51A and 51B of the notches 51 of the hard portion 42 of the linearmember 4 approach each other with the space therebetween in theextending direction. The hard portion 42 of the linear member 4 movescloser to the protruding portion 225 of the inner tube 22. The warpingof the linear member 4 is suppressed by the linear member 4 contracting.

As described above, when the notches 51 are formed in the linear member4 of the balloon catheter 10, the linear member 4 can be caused toappropriately extend over the whole length of the linear member 4 inaccordance with the inflation of the balloon 3. As a result, the ballooncatheter 10 can inhibit the linear member 4 from breaking away from theballoon 3 when the balloon 3 is inflated, or inhibit the linear member 4from obstructing the inflation of the balloon 3. Further, in the case ofthe balloon catheter 10, the end portion on the distal end side of thelinear member 4 is connected to the balloon 3, and the end portion onthe proximal end side of the linear member 4 is connected to thecatheter shaft 2 via the mounting member 21A. Other portions of thelinear member 4 are not bonded to the balloon 3. Further, when thelinear member 4 is bonded to the catheter shaft 2, a manufacturingprocess is easier than when the linear member 4 is bonded to the balloon3. Thus, the manufacturing of the balloon catheter 10 can be simplified.

In the above description, a part of the portion of the linear member 4excepting both the end portions on the distal end side and the proximalend side may be bonded to the balloon 3. For example, the second portion412 of the flexible portion 41 of the linear member 4 may be bonded tothe inflatable region 33 of the balloon 3.

Modified Examples

The present disclosure is not limited to the above-described embodimentsand various modifications are possible. The number of the linear members4, 6, 7, 8, and 9 is not limited to three, and may be another quantity.The linear members 4, 6, 7, 8, and 9 are members that extend in asubstantially straight line along the extending direction. In contrast,the linear members 4, 6, 7, 8, and 9 may be members that extend in aspiral shape along the extending direction. The hard portions 42 and 92may be provided across the whole length of the flexible portions 41 and91 in the extending direction.

The outer portions of the hard portions 42, 62 (the first portion 621),71 (the second portion 712), 82, and 92, which are each disposed in aposition corresponding to the inflatable region 33 of the balloon 3,correspond to the equilateral triangle shape and are peaked. The outerportions of the hard portions 42, 62, 71, 82, and 92 have the functionof suppressing the slipping of the balloon 3. The shape of the outerportions of the hard portions 42, 62, 71, 82, and 92 is not limited tothat of the above-described embodiments. For example, an angle of theouter portions of the hard portions 42, 62, 71, 82, and 92 may be steep.In this case, the outer portions of the hard portions 42, 62, 71, 82,and 92 may function, for example, as a cutting blade for cutting openthe lesioned part when the balloon 3 is in the inflated state.

The cross-sectional shape of the linear members 4, 6, 7, 8, and 9 is notlimited to the above-described examples. For example, thecross-sectional shape of the hard portions 42, 62, 71, 82, and 92 may bean isosceles triangle shape or a triangle shape having three sides ofmutually differing lengths. In the first embodiment, the cross-sectionalshape of the flexible portion 41 may be a semi-circle that is cut outfrom the outside, or may be a polygonal shape. The cross-sectional shapeincluding the flexible portion 41 and the hard portion 42 may be acircular shape, or may be a polygonal shape. Note that this also appliesto the second to ninth embodiments.

In the above-described embodiments, the end portions on the distal endside of the linear members 4, 6, 7, 8, and 9 are connected to the distalend side leg portion 35, at the distal end position M1. In contrast tothis, the end portions on the distal end side of the linear members 4,6, 7, 8, and 9 may be connected to the inner tube 22. The end portion onthe proximal end side of the linear member 4 is connected to themounting member 21A. The end portions on the proximal end side of thelinear members 6, 7, 8, and 9 are connected to the proximal end side legportion 31. In contrast to this, the end portions on the proximal endside of the linear members 4, 6, 7, 8, and 9 may be connected to theouter tube 21.

The end portion on the proximal end side of the linear member 4 need notnecessarily be able to move along the extending direction. Specifically,for example, the end portion on the proximal end side of the linearmember 4 may be connected to the outer peripheral surface of the outertube 21, further toward the proximal end side than the portion, of theouter tube 21, at which the proximal end side leg portion 31 of theballoon 3 is connected.

Each of the first directions D11, D21, D31, D41, and D51 is inclinedtoward the proximal end side with respect to the direction orthogonal tothe extending direction. Each of the second directions D12, D22, D32,D42, and D52 is inclined toward the distal end side with respect to thedirection orthogonal to the extending direction. In contrast to this,the first directions D11, D21, D31, D41, and D51 and the seconddirections D12, D22, D32, D42, and D52 may extend in the directionorthogonal to the extending direction. The preferable five degrees ofeach of the first angles θ11, θ21, θ31, θ41, and θ51 is smaller than thepreferable sixteen degrees of each of the second angles θ12, θ22, θ32,θ42, and θ52. In contrast to this, a preferable value of each of thefirst angles θ11, θ21, θ31, θ41, and θ51 may be the same as a preferablevalue of each of the second angles θ12, θ22, θ32, θ42, and θ52. Further,the preferable value of each of the first angles θ11, θ21, θ31, θ41, andθ51 may be larger than the preferable value of each of the second anglesθ12, θ22, θ32, θ42, and θ52.

The proximal end side thicknesses R11, R21, R31, and R41 are larger thanthe distal end side thicknesses R13, R23, R33, and R43. In contrast tothis, the proximal end side thicknesses R11, R21, R31, and R41 may bethe same as the distal end side thicknesses R13, R23, R33, and R43. Theproximal end side thicknesses R11, R21, R31, and R41 may be smaller thanthe distal end side thicknesses R13, R23, R33, and R43. The proximal endside thickness R51 may be larger or smaller than the distal end sidethickness R53.

The position of the boundary on the distal end side of the inflatableregion 33 is aligned, in the extending direction, with the position P11of the end portion on the distal end side of the marker 22A. Theposition of the boundary on the proximal end side of the inflatableregion 33 is aligned, in the extending direction, with the position P21of the end portion on the proximal end side of the marker 22B. However,the position of the boundary on the distal end side of the inflatableregion 33 need not necessarily be completely aligned, in the extendingdirection, with the position P11 on the distal end side of the marker22A. For example, the position of the boundary on the distal end side ofthe inflatable region 33 may be aligned, in the extending direction,with any position between the position P11 of the end portion on thedistal end side of the marker 22A and a position P12 of the end portionon the proximal end side of the marker 22A. The position of the boundaryon the proximal end side of the inflatable region 33 need notnecessarily be completely aligned, in the extending direction, with theposition P21 on the proximal end side of the marker 22B. For example,the position of the boundary on the proximal end side of the inflatableregion 33 may be aligned, in the extending direction, with any positionbetween the position P21 of the end portion on the proximal end side ofthe marker 22B and a position P22 of the end portion on the distal endside of the marker 22B. In other words, it is sufficient that thepositions of the marker 22A and the marker 22B respectively correspondto the position of the boundary on the distal end side of the inflatableregion 33 and the position of the boundary on the proximal end side ofthe inflatable region 33. Further, the number of the markers is notlimited to two, and may be three or more.

Each of the boundary portion between the proximal end side cone region32 and the inflatable region 33 and the boundary portion between theinflatable region 33 and the distal end side cone region 34 of theballoon 3 in the inflated state may be curved. In this case, forexample, with respect to the positions of each of the boundaries, when aplurality of virtual planes that touch the respectively curved boundaryportions are defined, positions of the boundary portions that touch thevirtual plane, of the plurality of virtual planes, that forms an acuteangle of 45 degrees with the extending direction may be the positions ofeach of the boundaries. Further, in the above-described embodiments,each of the proximal end side cone region 32 and the distal end sidecone region 34 is a region whose diameter changes linearly from theproximal end side toward the distal end side. However, each of theproximal end side cone region 32 and the distal end side cone region 34may be a region whose diameter changes in a curved manner from theproximal end side toward the distal end side. In addition, one of theproximal end side cone region 32 and the distal end side cone region 34may be the region whose diameter changes in the curved manner and theother may be the region whose diameter changes linearly.

The distal end surfaces 42S, 62S, 72S, 82S, and 92S, and the proximalend surfaces 42K, 62K, 72K, 82K, and 92K of the linear members 4, 6, 7,8, and 9 need not necessarily have a straight line shape. For example,at least either of the distal end surfaces 42S, 62S, 72S, 82S, and 92S,or the proximal end surfaces 42K, 62K, 72K, 82K, and 92K may have leveldifferences.

The outer portions 412B and 912B have a straight line shape. The outerportions 412B and 912B may have a curved shape. In other words, forexample, the hard portions 42 and 92 may have a circular arc-shapedcross section.

The present disclosure can be applied to a device other than the ballooncatheter that includes the balloon 3 that is inflated by the supply ofthe compressed fluid. For example, the linear members 4, 6, 7, 8, and 9may be applied to a device that has a mechanically expanding mechanismin place of the balloon 3. In the above-described embodiments, theexample is given of the catheter shaft 2 that has the outer tube 21 andthe inner tube 22. In the present disclosure, the catheter shaft 2 neednot necessarily have the outer tube 21 and the inner tube 22. Forexample, the catheter shaft 2 may have only one flexible tube.

In the sixth to ninth embodiments, the positions in the radial directionof the bottom portions 51C to 53C of each of the notches 51 to 53, andthe bottom portions 54C of the incisions 54 may be positions that aresubstantially the same position as the inner portion 912A of the secondportion 912 of the flexible portion 91. In other words, the linearmember 9 may be divided in the extending direction by the notches 51 to53 or the incisions 54.

In the sixth to eighth embodiments, the cross-sectional shape of thenotches 51 to 53 is not limited to the wedge shape. For example, a notchmay be a slit whose cross-sectional shape is a semi-circular shape, arectangular shape, a trapezoid shape or the like, or may be a slit whoseoutside end portions are rounded. Further, a plurality of slits havingmutually different cross-sectional shapes may be formed in the linearmember 9. When the notch has the semi-circular shape, the rectangularshape, the trapezoid shape or the like, the position of a bottom portionthereof may be further to the inside or to the outside, in the radialdirection, than the boundary 912B between the second portion 912 of theflexible portion 91 and the hard portion 92. In addition, the positionof the bottom portion may be a position that is substantially the sameposition as the boundary 912B in the radial direction. The number of thenotches 51 to 53 formed in the linear member 9 is not limited to two,and may be another quantity, such as one or more, for example.

In the ninth embodiment, the incision 54 may extend in a directionintersecting with the radial direction, to the inside from the outerportion 92B of the hard portion 92. The shape of the incision 54 is notlimited to the straight line and may be a curved line. The incision maybe a slit whose outside end portions are rounded. Further, a pluralityof slits including the notches and the incisions having mutuallydifferent shapes may be formed in the linear member 9.

In the sixth to ninth embodiments, the linear member 9 may be bonded tothe balloon 3 only in the vicinity of each of the distal end position M1and the proximal end position M2. Of the linear member 9, a sectionexcluding the vicinity of each of the distal end position M1 and theproximal end position M2 need not necessarily be bonded to the balloon3. The end portion on the distal end side of the linear member 9 may beconnected to the inner tube 22. The end portion on the proximal end sideof the linear member 9 may be connected to the outer tube 21.

In the sixth to ninth embodiments, the flexible portion 91 of the linearmember 9 includes the first portion 911, the second portion 912, and thethird portion 913. However, the flexible portion 91 need not necessarilyinclude the first portion 911 and the third portion 913. For example,the linear member 9 may be configured by the hard portion 92 and thesecond portion 912. In this case, the second portion 912 is bonded withthe outer peripheral surface of the inflatable region 33 of the balloon3 using adhesive or the like. In addition, the flexible portion 91 ofthe linear member 9 may be configured by the second portion 912 and oneof the first portion 911 and the third portion 913.

The apparatus and methods described above with reference to the variousembodiments are merely examples. It goes without saying that they arenot confined to the depicted embodiments. While various features havebeen described in conjunction with the examples outlined above, variousalternatives, modifications, variations, and/or improvements of thosefeatures and/or examples may be possible. Accordingly, the examples, asset forth above, are intended to be illustrative. Various changes may bemade without departing from the broad spirit and scope of the underlyingprinciples.

What is claimed is:
 1. A balloon catheter comprising: a balloon/shaftassembly that includes a catheter shaft extending from a proximal end toa distal end and a balloon connected to the catheter shaft, the balloonhaving an inflatable region configured to inflate outward in a radialdirection around the catheter shaft; and a linear member straddling theinflatable region of the balloon and being mounted on the balloon/shaftassembly at a distal end position located further toward a distal endside than the inflatable region and at a proximal end position locatedfurther toward a proximal end side than the inflatable region, whereinthe linear member includes: a hard portion that includes at least anouter portion disposed on an opposite side to an inner portion facingthe inflatable region, of a portion disposed along an outer peripheralsurface of the inflatable region in an inflated state, and a flexibleportion that is a portion other than the hard portion, the flexibleportion being extendable and having a hardness lower than the hardportion, wherein the flexible portion extends between the distal endposition and the proximal end position, wherein the hard portionprotrudes to the outside from the outer portion of a portion of theflexible portion that is disposed along the outer peripheral surface ofthe inflatable region in the inflated state, and wherein, a thickness ofa portion of the flexible portion, which is located further toward thedistal end side than the hard portion, is narrower than a thickness of aportion of the flexible portion located further toward the proximal endside than the hard portion.
 2. The balloon catheter according to claim1, wherein a slit is formed extending toward the inside in the radialdirection from an end portion on the outside of the hard portion.
 3. Theballoon catheter according to claim 1, wherein a direction extending tothe outside along a distal end portion is inclined toward a proximal endside, the distal end portion being an end portion on the distal end sideof the hard portion.
 4. The balloon catheter according to claim 1,wherein a direction extending to the outside along a proximal endportion is inclined toward the distal end side, the proximal end portionbeing an end portion on the proximal end side of the hard portion. 5.The balloon catheter according to claim 1, wherein a first directionextending to the outside along a distal end portion is inclined towardthe proximal end side, the distal end portion being an end portion onthe distal end side of the hard portion, a second direction extending tothe outside along a proximal end portion is inclined toward the distalend side, the proximal end portion being an end portion on the proximalend side of the hard portion, and an angle of the first direction withrespect to an extending direction of the catheter shaft is smaller thanan angle of the second direction with respect to the extending directionof the catheter shaft.
 6. The balloon catheter according to claim 2,wherein the slit is a notch where a part of the linear member is cutout.
 7. The balloon catheter according to claim 2, wherein the slit isan incision having two surfaces that face each other and are in contactwith each other.
 8. The balloon catheter according to claim 1, whereinat least a part of the flexible portion of the linear member is bondedto the balloon.
 9. The balloon catheter according to claim 1, whereinthe linear member is disposed along an outer peripheral surface of theballoon in the inflated state.
 10. The balloon catheter according toclaim 1, wherein two radiopaque markers are respectively provided in twopositions separated from each other in an extending direction of thecatheter shaft, of the two radiopaque markers, a position of a markerprovided on the distal end side corresponds to a position of a boundaryof the inflatable region on the distal end side, in the extendingdirection of the catheter shaft, and of the two radiopaque markers, aposition of a marker provided on the proximal end side corresponds to aposition of a boundary of the inflatable region on the proximal endside, in the extending direction of the catheter shaft.
 11. The ballooncatheter according to claim 1, wherein the balloon includes a proximalend side leg portion bonded to the catheter shaft at a position furthertoward the distal end side than the proximal end position, and an endportion on the proximal end side of the linear member is bonded to theballoon/shaft assembly at the proximal end position.
 12. The ballooncatheter according to claim 1, wherein the balloon includes a proximalend side leg portion bonded to the catheter shaft at the proximal endposition, and an end portion on the proximal end side of the linearmember is bonded to an outer peripheral surface of the proximal end sideleg portion.
 13. The balloon catheter according to claim 1, wherein thelinear member is formed of a synthetic resin.
 14. The balloon catheteraccording to claim 1, wherein the linear member includes end portions inan extending direction, at least one of the end portions being connectedto the catheter shaft.
 15. The balloon catheter according to claim 1,wherein the thickness of the portion of the flexible portion locatedfurther toward the distal end side than the hard portion is constant.